Top feed belt apparatus for a sewing machine

ABSTRACT

There is provided in a sewing machine, a top feed belt apparatus for pulling material in a direction of sewing. The top feed belt apparatus includes a top feed belt for contacting the material, and a tool-less, manual adjustment device for providing a tool-less, indexed, manual adjustment to a motion of the top feed belt based on an operator input.

FIELD OF THE INVENTION

[0001] The present invention generally relates to sewing machines and, more particularly, to a top feed belt apparatus for a sewing machine. The top feed belt apparatus provides auxiliary pulling in the direction of sewing for thick and lofty materials, while allowing for tool-less, on-the-fly adjustments.

BACKGROUND OF THE INVENTION

[0002] An eccentric driven top feed belt has been employed in prior art sewing machines to provide auxiliary pulling in the direction of sewing for thick and lofty materials. The use of the eccentric driven top feed belt requires the production of indexed rotary motion to drive the eccentric driven top feed belt. Eccentric motion is supplied by an eccentric assembly, which converts straight rotary motion from the sewing machine drive shaft into eccentric motion. This motion is then transferred to a ratcheting clutch arm that indexes a timing pulley and consequently, the eccentric driven top feed belt.

[0003] There is an inherent problem in the above prior art eccentric driven top feed belt system, in so far as adjustability is concerned. It becomes necessary from time to time to adjust the eccentricity of the motion, and change the range of index motion. This operation required hand tools, and an increased knowledge of the mechanism's operating principles. Adjustments often require one half hour or more of time to implement, during which time the sewing machine is not running in production.

[0004] Accordingly, it would be desirable and highly advantageous to have a top feed belt apparatus capable of allowing an operator to make tool-less, on-the-fly adjustments to the motion of the top feed belt.

SUMMARY OF THE INVENTION

[0005] The problems stated above, as well as other related problems of the prior art, are solved by the present invention, a top feed belt apparatus for a sewing machine. The top feed belt apparatus provides auxiliary pulling in the direction of sewing for thick and lofty materials, while allowing for on-the-fly adjustments with hand tools.

[0006] According to an aspect of the present invention, there is provided in a sewing machine, a top feed belt apparatus for pulling material in a direction of sewing. The top feed belt apparatus includes a top feed belt for contacting the material, and a tool-less, manual adjustment device for providing a tool-less, indexed, manual adjustment to a motion of the top feed belt based on an operator input.

[0007] These and other aspects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a diagram illustrating a top feed belt apparatus for a sewing machine, according to an illustrative embodiment of the present invention;

[0009]FIG. 2 is a diagram illustrating a locking assembly of the top feed belt apparatus of FIG. 1, according to an illustrative embodiment of the present invention;

[0010]FIG. 3 is a diagram illustrating a front view of the top feed belt apparatus of FIG. 1, according to an illustrative embodiment of the present invention;

[0011]FIG. 4 is a diagram illustrating a groove that a top feed belt follows as it turns under a material clamp, according to an illustrative embodiment of the present invention; and

[0012]FIG. 5 is a diagram illustrating a top feed belt apparatus, according to another illustrative embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention is directed to a top feed belt apparatus for a sewing machine. The top feed belt apparatus provides auxiliary pulling in the direction of sewing for thick and lofty materials, while allowing for tool-less, on-the-fly adjustments. For example, the present invention may be readily employed to pull materials having a minimum thickness of at least one inch. Of course, thinner materials may also be used.

[0014] The top feed belt apparatus of the present invention achieves at least the same desired results as the prior art eccentric driven top feed belt with respect to auxiliary puling, but with two main advantages. First, adjustments can be made on the fly with no loss in production speed. Secondly, the unit can be adjusted by operators with no mechanical skill, eliminating the need for hand tool/mechanic adjustments.

[0015]FIG. 5 is a diagram illustrating a top feed belt apparatus 500, according to an illustrative embodiment of the present invention. The top feed belt apparatus 500 includes a top feed belt 510. Moreover, the top feed belt apparatus 500 advantageously includes a tool-less, manual adjustment device 520 for providing a tool-less, indexed manual adjustment to the motion of the top feed belt 510 based on an operator input. The tool-less, manual adjustment device 520 may include, but is not limited to, at least one of, for example, a stepper motor 532, a servomotor 534, and a mechanical linkage 536. Any of the stepper motor 532, the servomotor 534, and the mechanical linkage 536 may be employed by the present invention for adjusting the motion of the top feed belt 510 in response to the operator input. For illustrative purposes, the stepper motor 532, the servomotor 534, and the mechanical linkage 536 are all shown as included in the tool-less, manual adjustment device 520. However, it is to be appreciated in other embodiments of the present, only one (or any number more than one) of the preceding elements may be included in the tool-less, manual adjustment device 520 while maintaining the spirit and scope of the present invention.

[0016] A sewing machine in which the top feed belt apparatus 500 of the present invention is employed may include a feeding mechanism 590, separate from the top feed belt apparatus 500, for feeding material 550 into a sewing area of the sewing machine in conjunction with the top feed belt apparatus 500. The feeding mechanism may include at least one of, for example, a feed dog and a belt. The tool-less, manual adjustment device 520 allows an operator to synchronize the top feed belt 510 with the feeding mechanism 590 of the sewing machine based on the operator input.

[0017] The tool-less, manual adjustment device 520 allows for adjustments to be made to the top feed belt 510 that take into account characteristics of the material 550 to be sewed. Such characteristics include, but are not limited to, for example, the number of layers of the material to be sewed, the pattern to be sewed on the material, the elasticity of one or more layers of the material, and the coefficient of friction of one or more layers of the material.

[0018] For illustrative purposes, the present invention will be described below with respect to the mechanical linkage 536. However, as noted above, other devices may be employed in place of, or in addition to, part or all of the mechanical linkage 536. Such other devices include, but are not limited to, stepper motors and servomotors as noted above.

[0019] In an illustrative embodiment of the present invention, the top feed belt apparatus of the present invention can be considered an eccentric-to-rotary motion assembly for providing indexed rotary motion from eccentric motion, to pull material in a direction of sewing. The eccentric-to-rotary motion assembly can be considered to include an eccentric motion generator for generating eccentric motion from rotary motion, an indexed rotary motion generator for generating indexed rotary motion from the eccentric motion, and a multi-bar linkage for providing on-the-fly adjustments to the eccentric motion to maintain a pre-determined range for the indexed rotary motion.

[0020] In general, the multi-bar linkage can be considered to include a plurality of adjustable pivot points having an adjustable geometry, an adjustment assembly for adjusting the geometry of the plurality of adjustable pivot points, and a locking assembly for locking and unlocking the adjustment assembly.

[0021] A further description will now be given of various aspects of the present invention with respect to FIGS. 1-4 below.

[0022]FIG. 1 is a diagram illustrating a top feed belt apparatus 100 for a sewing machine, according to an illustrative embodiment of the present invention.

[0023] Eccentricity is generated by an offset cam 105, which takes power off of a main sewing machine drive shaft 110. The eccentric motion is then transferred to a connecting arm 115 thru a driven shaft 120. The connecting arm 115 then drives a ratchet clutch assembly 125, producing indexed rotary motion that is then transferred to a timing belt pulley drive shaft 130 and consequently, a top feed belt 510 (shown in FIG. 4) that is operatively coupled to timing belt pulley drive shaft 130.

[0024] There is a four bar linkage formed between ratchet clutch assembly 125, connecting arm 115, a pivot yoke 140, and dog bone connecting links 145. The four pivot points include driven shaft 120, a ratchet shaft 122 (that connects connecting arm 115 to ratchet clutch assembly 125), a secondary shaft 155 and timing belt pulley drive shaft 130. If these points were all grounded and permanent, the resultant motion would be fixed. However, when a degree of freedom is added, the four bar linkage can be manipulated to produce a range of indexed rotary motion (OUTPUT) based on a fixed eccentric motion (INPUT).

[0025] The pivot yoke 140 is allowed to rotate within a fixed range, and is locked when a desired range of indexed rotary motion is achieved. The pivot yoke 140 is normally locked and fixed in position by a locking assembly 170 that includes, among other parts, a split clamp assembly 180. The locking assembly 170 is described in further detail below with respect to FIG. 2.

[0026] It is to be appreciated that dog bone connecting links 145, which are coupled to secondary shaft 155, act to transfer indexed rotary motion to connecting arm 115. A first assembly wall 198, a second assembly wall 199, and an oil seal 197 are shown in FIG. 1.

[0027]FIG. 2 is a diagram illustrating locking assembly 170 of top feed belt apparatus 100 of FIG. 1, according to an illustrative embodiment of the present invention. A pneumatic actuator 210 (hereinafter interchangeably referred to as” actuator locking cylinder”) normally applies air pressure to a locking arm 215 that drives a locking stud 220. The locking stud 220 applies clamp pressure to an upper split clamp 225 and a lower split clamp 230. The upper split clamp 225 and lower split clamp 230 form split clamp assembly 180. When clamped together, upper split clamp 225 and lower split clamp 230 apply locking pressure to a locking disc 235. The locking disc 235 is locked to a pivot shaft 160, which is also locked to pivot yoke 140. When the operator depresses a lock release push button 165, a pneumatic valve (solenoid actuated) reverses pneumatic actuator 210, which opens split clamp assembly 270 (that includes the upper split clamp 225 and the lower split clamp 230), releasing pivot shaft 160 from ground and allowing the operator to rock a power shift knob 175 within the constraints of its range of motion. When the operator releases lock release push button 165, the pneumatic actuator valve returns to its de-energized state and re-clamps upper split clamp 225 and lower split clamp 230.

[0028] When pivot yoke 140 is rotated, the X-Y coordinate of secondary shaft 155 is changed, transforming the geometry of the four-bar linkage described above. By manipulating this position, a desired result is achieved in the output of the system via the resultant indexed rotary motions. The system was designed to duplicate what a mechanic could achieve in the field with respect to the prior art systems within the constraints of the mechanical adjustments available on the older style system.

[0029]FIG. 3 is a diagram illustrating a front view of top feed belt apparatus 100 of FIG. 1, according to an illustrative embodiment of the present invention. A main drive pulley 310 is coupled to the main sewing machine drive shaft 110. The power shift knob 175 moves along a sliding indicator assembly 320 having a relative indicator 350 adjacent thereto. The relative indicator 350 provides a relative indication of a maximum and minimum position for operator reference.

[0030] The contact point of the top feed belt 510 is also unique, in its point of line contact relative to the position of the sewing machine needles.

[0031] In previous versions of the machines design, the eccentric driven top feed belt was laced in such a way as to contact the material upwards of an inch or more in front of the needle penetration area. This design impeded operators efforts to turn corners easily, as this 1″+ of lone contact resisted the turn, holding the material in place and biasing its ability to pivot.

[0032] According to the present invention, the top feed belt 510 wraps in such a way as to contact the material directly in line with the needle penetration area, enhancing the ability to turn on that precise pivot point. FIG. 4 is a diagram illustrating the groove that top feed belt 510 follows as it turns under a material clamp 470, according to an illustrative embodiment of the present invention. The point of tangent contact 499 is established directly between the two needle slots 482 and 483 and not out in front as in previous models.

[0033] With the present invention, the top feed belt 510 retains its advantage of helping the material track straight as the long sides of a quilted panel are sewn, by maintaining its linear geometry. By changing the point of “tangent” contact however, to line up directly with the needles (and consequently the pivot point) the unit gains a tremendous advantage when the operator turns.

[0034] Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one of ordinary skill in the related art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims. 

What is claimed is:
 1. In a sewing machine, a top feed belt apparatus for pulling material in a direction of sewing, the top feed belt apparatus comprising: a top feed belt for contacting the material; and a tool-less, manual adjustment device for providing a tool-less, indexed, manual adjustment to a motion of the top feed belt based on an operator input.
 2. The top feed belt apparatus of claim 1, wherein said tool-less manual adjustment device comprises a stepper motor for adjusting the motion of the top feed belt in response to the operator input.
 3. The top feed belt apparatus of claim 1, wherein said tool-less manual adjustment device comprises a servomotor for adjusting the motion of the top feed belt in response to the operator input.
 4. The top feed belt apparatus of claim 1, wherein said tool-less manual adjustment device comprises a mechanical linkage for adjusting the motion of the top feed belt in response to the operator input.
 5. The top feed belt apparatus of claim 1, wherein the sewing machine comprises a feeding mechanism for feeding the material into a sewing area of the sewing machine in conjunction with said top feed belt, and said tool-less manual adjustment device is capable of synchronizing the top feed belt with the feeding mechanism of the sewing machine based on the operator input.
 6. The top feed belt apparatus of claim 5, wherein the feeding mechanism comprises at least one of a feed dog and a belt.
 7. The top feed belt apparatus of claim 1, wherein said tool-less manual adjustment device is capable of accounting for characteristics of the material to be sewed in adjusting the motion of the top feed belt based on the operator input.
 8. The top feed belt apparatus of claim 1, wherein said tool-less manual adjustment device, in adjusting the motion of the top feed belt based on the operator input, is capable of accounting for at least one of a number of layers of the material to be sewed, a pattern to be sewed on the material, an elasticity of at least one of the layers of the material, and a coefficient of friction of at least one of the layers of the material.
 9. The top feed belt apparatus of claim 1, wherein the top feed belt is capable of pulling the material having a minimum thickness of at least one inch.
 10. The top feed belt apparatus of claim 1, wherein the sewing machine comprises a needle penetration area, and said top feed belt is adapted to contact the material directly in line with the needle penetration area, to pull the material in the direction of sewing and allow turning of the material at the needle penetration area.
 11. In a sewing machine, a method for adjusting a top feed belt, the top feed belt for pulling material in a direction of sewing, the method comprising the steps of: providing a capability for tool-less, indexed, and manual adjustment of a motion of the top feed belt based on an operator input.
 12. The method of claim 11, wherein said providing step comprises the step of providing a capability to control a stepper motor to adjust the motion of the top feed belt in response to the operator input.
 13. The method of claim 11, wherein said providing step comprises the step of providing a capability to control a servomotor to adjust the motion of the top feed belt in response to the operator input.
 14. The method of claim 11, wherein said providing step comprises the step of providing a capability to control a mechanical linkage to adjust the motion of the top feed belt in response to the operator input.
 15. The method of claim 11, wherein the sewing machine comprises a feeding mechanism for feeding the material into a sewing area of the sewing machine in conjunction with said top feed belt, and said providing step comprises the step of providing a capability to synchronize the top feed belt with the feeding mechanism of the sewing machine based on the operator input.
 16. The method of claim 11, wherein said providing step comprises the step of providing a capability to account for characteristics of the material to be sewed in adjusting the motion of the top feed belt based on the operator input.
 17. The method of claim 11, wherein said providing step, in providing the capability for tool-less, indexed, and manual adjustment of the motion of the top feed belt based on the operator input, comprises the step of providing the capability to account for at least one of a number of layers of the material to be sewed, a pattern to be sewed on the material, an elasticity of at least one of the layers of the material, and a coefficient of friction of at least one of the layers of the material. 